1. Field of the Invention
The present invention relates to an image processing device for analyzing and processing acquired images and to an image processing method used in the device.
2. Description of the Related Art
Image analysis technologies using principal component analysis for the purpose of recognizing a pattern of a subject (e.g. a human face), compressing data, etc., are proposed (see, for example, Japanese Patent Laid Open Publication 2004-7274). Principal component analysis is one type of multivariate analysis and is capable of deriving a dominant factor in interpreting a distribution by identifying an eigenvector having a large eigenvalue from a correlation matrix or a variance-covariance matrix of a multidimensional vector. Principal component analysis as applied to image analysis is capable of recovering an original image from a small amount of data or identifying similarity between images, by using pixel values of an image as input data and using linear coupling of eigenvectors calculated from the data.
Principal component analysis is extremely useful means in the field of image processing in that it is capable of systematically understanding the overall characteristic of an image that a human being can normally perceive at a glance. However, principal component analysis requires pixel values as input data and so involves a far larger amount of parameters as compared with ordinary information analysis. This results in a problem in that, the higher the resolution of an image subject to processing, the narrower the scope of application of the technology due to the constraints on processing capabilities and resources of the device.